Chair-iron



W. LOEFFLER.

cum mow. APPLICATION FILED FEB. 5, 1919.

1,334,660. Patented Mar. 23; 1920.

w J mm #20.

WITNESSES.

ATTOQNEY WILLIAM LOEFFLER, OF SHEBOYGAN, WISCONSIN.

CHAIR-IRON.

Specification of Letters Patent.

Patented Mar. 23, 1920.

Application filed February 5, 1919. Serial No. 275,227.

To all whom it may concern:

Be it known that I, WILLIAM Lonrrnnn, a citizen of the United States, and'resident of Sheboygan, in the county of Sheboygan and State of Wisconsin, have invented new and useful Improvements in Chair-Irons, of which the following is a description, refer ence being had to the accompanying drawings, which are a part oi: this specification.

This invention relates to chair irons more particularly? for use on desk and other swivel chairs in which it is desired to adjust the height 01'' the chair bottom and maintain it in its adjusted position.

Generally in chair irons a handwheel outside the body portion of the chair iron is used to raise and lower the screw spindle and after the adjustment is made said wheel is locked with the screw spindle supporting the chair. Such constructions from the users standpoint are obj ectionable because it is both a troublesome and dirty task to manipulate the handwhecl. To obviate this ditliculty I have provided a chair iron in which the adjustment ismade by rotating the chair itself and in which the parts are locked in adjusted position by a locking means within the body of the chair iron c011- trollcd by a slight movement of a lever conveniently located for manipulation. by the operator.

A further object of the invention is to provide an expan'sible locking means within the body of the chairiron and engageable therewith to secure the spindle in adjusted position and which may be quickly unlocked and clamped to the lower end of the spindle to raise or lower said spindle by rotation.

The invention further consists in the several features hereinafter set forth and shown and described in the accompanying drawings in which:

Figure 1 is a vertical sectional view through the device embodying the invention;

Fig. 2 is a plan view thereof; a

Fig. Sis an enlarged view of the locking means shown in Fig. 1;

Fig. l is a detail sectional view through the locking means; a

Fig. 5 isa plan view of the upper end of the spindle;

b Fig. 6 is a side view of the upper-end of the spindle;

Fig. 7 is a viewsimilar to Fig. 3 showing amodiiied term of locking means, parts being broken away; and, 1

Fig. 8 is a detail bottom View of the looking member shown in Fig. 7

In the drawings the numeral 9 designates the nut member of the iron, 10 the spindle and 11 the spider having supporting arms 12 adapted to be secured to the chair bottom in the usual manner.

As is usual the spider 11 is pivotally mounted upon bolts 13 passing through spaced apart cars 14- on the upper portion of the spindle to provide for tilting the chair seat, which tilting is resisted by a spring 15 mounted on a rod 16 between a flange portion 17 on the spider and an adjustableknob 18 mounted on the threaded end of the rod 16. The rod 16 is secured at its inner end 19 upon a transverse web 20 of the spindle which, contrary to the usual practice, is slightly offset from the center of the spindle for the purpose of permitting bolt 4.2 to pass down and through the spindle 10. This construction permits the spider to be tilted rearwardly upon the spindle against the action of the spring 15. Forward tilting movement of the spider with respect to the spindle is prevented by steps 21 on the head of the spindle engageable with the rear ends of slots 22 in the web portion 23 of the spider.

The nut member 9 of the chair iron is provided with a threaded bore 24: extending the length thereof and the cylindrical stem 25 of the spindle 10 is freely revolubly mounted in said here. A cap 9 removably covers the lower end of the bore and pre vents oil from leaking out of said bore.

The spindle 10 is supported in the bore 2st by locking means engageable with the nut and adapted to be moved relatively to the body 9 to secure the spindle in difi'erent positions of vertical adjustment.

Referring to Figs. 3 and a the locking means consists oi a threadedscrew made up of two parts 26 and 27 securable together to act as a unit by an interlocking connection such as tongues 28 on the part 26 and grooves 29 011 the part 27. When said parts are secured together to act as a unit, the screw is free to be turned in the nut and the lower end 30 of the spindle, which may rest upon a washer 31 on the top of the part 26 of the screw in the desired direction. Normally the threaded screw is prevented from turning in the nut by means tending to separate the two parts 26 and 27 and cause them to bind on the threads of the bore 2a. Th s means consists of a spring 32 seated within '4 the bolt 42 passes through apertures 47 registering recesses 33 and 34 in the. parts 26 and 27 and bearing at 1ts ends against said parts to separate them and thus cause them to bind'on the threaded portion of the bore. In this manner the separation of the parts of the screw lengthwise of the .37 and 38 and likewise permit said parts to be contracted when pressure is applied to draw'them together along the line of the cut. When the parts 37 and 38 are drawn together the scr'ew is'free to turn in the nut 24 and-the lowerend 30 of the spindle, which rests upon a washer 31 on the top of said screw, is therebyraised or lowered by the turning of the screw in the desired di 'rection. V

' Normally the screw35 is prevented from turning in the bore by means tending to separate the parts 37 and 38 and cause them to bind widthwise on the threads of the nut. This means consists of a Spring ring 39 seated in a recess 40 in the member 35 and bearing against an annular shouldered portion 41 formed thereby.

Thus in both forms the screw is normally held in locked position and the spindle is free to revolve upon the supporting screw and within the bore 24 of the nut member 9 of theironp To release the screw from looking engagement with the nut means are provided which are controlled from without the nut and in each instance consists of means for counteracting the actions of the springs 32 or 39.

' In both of these forms a spindle bolt 42 passes downthrough stem 25 of the spindle and through a central aperture or apertures in the screw and has a cam locking lever 43 mounted on its upper end. This lever 43 has an inclined'cam -face 44 cooperating with an inclined face 45011 the head of the spindle so as to move said bolt'42 upwardly when said lever 43 is turned and to secure it in elevated position and the screw to the spindle 10 as thei'ace 44 rides up on the taco 45, as shown in Fig. 6.

Normally the the lever is held in inoperative position by means of a spring 46 connected at one end to the head of the lever and at its other end to the spindle. The lever 43 and bolt 42 form in effect a nut clamp.

In the construction shown in Figs. 3 and and 48in the parts=26 and 27 and carries a washer 49 movable into contact with the bottom of the member 27, and resting on. nuts 50. With this construction the. upward movement of the bolt 42 in the manner above described, causes the washer 49 to engage the part 27 and thereafter move said part into locking engagement with the part 26 against theaction of the spring 82 and thus cause the screw to act as a unit and be locked with the spindle 10 so that it is free to be turned therewith.

In the construction shown in Figs. 7 and 8 the member 35 has a conical head 51 adjacent the recess 40 and the bolt 42 carries a washer 52 having a conical recess 53 therein in which the lower end of the conical head 51 is seated. lVit-h this construction the upward movement of the bolt 42 in the manner above described, causes the washer 52 to move up into clamping engagement with the head 51 and thereby, due to its wedging action, draws the parts 37 and 38 of the screw member together and clamp same to the spindle 10 and thus render the screw free to turn in the threaded bore 2! on a rotation of the spindle.

In either case after the spindle has been the cam lock and the screw supporting means for the spindle is thereby locked in the nut and the spindle is free to rotate thereon.

It will be noted that the lever 43 is conveniently located on the spindle in easy reach of the occupant of the chair so that on the release ot'the nut from locking engagement with the threaded bore of the iron the height of the spindle may be adjusted by turning around the chair scat.

lVhat I claim as new and desire to secure Letters Patent is:

1. In a chair iron, the combination, with the nut member, of a. smooth spindle revolubly mounted within the bore of said member, and means for supporting the spindle in different positions of vertical adjustment comprising expansible means lockingly engaging the sides of the nut member in different positions of vertical adjustment, andmeans for releasing said e.\'pansible means from locking engagement with said member to change the adjustment.

2. In a chair 11011, the combination ol a nut member having a threaded bore therein,

a smooth spindle freely rcvolubly mounted within the bore, and supporting means {or the spindle adj ustably mounted in the bore comprising expansible means having a threaded portion lockingly engaging some of the threads of the bore, and means vfor contracting said expansible means to permit 1t to turn freely in the bore and be moved locking position,

normally acting to expand the screw memher to lockingly secure it within the nut member, a smooth spindle revolubly mounted in the nut member and supported by said screw member, and means for contracting said screw member to permit its being turned in the nut to vary the position of the spindle with respect to said nut member.

In a chair iron, the combination of a nut member having a threaded bore therein, an expansible screw having parts lockingly engageable with threads of the bore, means normally maintaining said parts in locking position, a smooth spindle revolubly mounted in the bore and supported by said screw, and means for releasing said parts from locking engagement with the bore to permit raising or lowering of said screw and spindle with respect to said nut member.

5. In a chair iron, the combination of a nut member having a threaded bore therein, an eXpansible screw having parts lockingly engageable with threads of the bore, means normally maintaining said parts in a smooth spindle revolubly mounted in the bore and supported by said screw, and means controlled from without the bore for releasing said parts from locking engagement with the bore to permit raising and lowering of said screw and spindle with respect to said nut member.

6. In a chair iron, the combination of a nut member having a threaded bore therein, an expansible screw having parts locking-1y engageable with threads of the bore, a spring normally maintaining said parts in locking position, a spindle revolubly mounted in the bore and supported by said screw, and means for counteracting the aclieu of said spring and releasing said parts from locking engagement with the bore and cl amping mit raising or lowering of said screw and spindle by rotation of said spindle with respect to said nut member.

7. In a chair iron, the combination of a nut member having a threaded bore therein, an expansible screw, means normally maintaining said screw in looking engage ment with the bore, a spindle revolubly mounted in the bore and supported by said screw, and means carried by the spindle 'ifor contracting said screw and clamping it to said spindle to permit said screw and spindle being turned in the bore to vary the vertical position of the spindle.

8. In a chair iron, the combination oi a nut member having a threaded bore therein, an expansible screw having parts lockingly engageable with threads of the bore, a spring normally maintaining said parts in locking position, a spindle revolubly mounted in the bore and supported by said said parts to the spindle to per screw, a rod carried by the spindle and operatively connected to said screw, and a lever mounted on said rod at the upper portion of the spindle and adapted to move said rod and thereby release said parts from locking engagement with the bore and clamping said parts to the spindle to permit raising or lowering of said screw and spindle by rotating the chair.

9. In a chair iron, the combination of a nut member having a threaded bore, a screw having adiametrically extending slit therein and threaded parts lockingly engageable with the threads of the bore, a spring nor mally maintaining said parts in locked position, wedging means for contracting the parts adjacent the slit to permit free turning of the screw within the nut member, and a spindle mounted in the bore and supported by the screw.

10. In a chair iron, the combination of a nut member having a threaded bore, a screw having threaded parts separable from each other, a spring for normally separating said parts to cause said parts to lockingly eugage the nut member, means for moving said parts together to permit free turning ofthe screw within the bore, and a spindle revolubly mounted in the bore and supported by the screw.

11. In a chair iron, the combination of a nut member having a threaded here, an expansible screw mounted within the bore, means normally n'iaintaining said screw in locking engagement with said threaded bore, a spindle revolubly mounted in the bore and supported by said screw, and means for releasing said screw from locking engagement with the bore including a rod carried by the spindle, a lever mounted on the rod, and a cam connection between said lever and spindle to move said rod upwardly to release the screw and clamp it to the spindle in released position to permit turning of the screw to raise or lower the spindle by rotation of the chair.

12. In a chair iron, the combination of a nut member having a threaded bore, an expansible screw mounted within the bore, means normally maintaining said screw in locking engagement with the threaded bore, means permitting free t'tu'uing of the screw within the bore, a spindle revolubly mounted in the bore and supported by the screw, and a cap slidably fitting over the lower end of said nut member and covering the bore thereof.

In testimony whereof, I ailix my signature, in presence of two witnesses.

WILLIAM LOEFFLER.

lvitnesses WM. X. Lonrrnnn, LELAND ZIMM'ERMANN. 

